Albinism is a term used to describe a group of genetic disorders that have in common their reduction of ocular and often cutaneous pigmentation. These disorders can be associated with significant ocular morbidity. The ultimate goal of this research is to understand how mutations at genetic loci that control pigmentation can result in albinism. Four genetic loci known to interact in controlling melanogenesis and to be implicated in various forms of ocular and ocular cutaneous albinism are albino (c), brown (b), slaty (slt), and pink-eyed dilution (p). To accomplish their goals, the applicants propose to combine the power of mouse genetics with techniques of cell and molecular biology and biochemistry. They propose to study eyes and skin from inbred mice of defined genotype, melanocytes cultured from inbred mice, and nonmelanocytic and melanocytic cells of defined genotype transfected with expression vectors encoding specific melanosomal proteins singly and in combination. Chemical crosslinking and the yeast "two hybrid" system will also be employed to gain further insights into interactions among these melanosomal proteins.